Heat exchanger with reinforced neck

ABSTRACT

A heat exchanger assembly comprising a heat exchanger with tank having a neck, and, in various embodiments, an assembly further comprising a hose to form a hose-neck connection is provided. 
     A heat exchanger assembly comprising a hose-neck connection, having the advantage of providing for a connection resistant to temperature and pressure conditions of heat exchangers is provided. 
     By providing for particular rib patterns on the neck, an optimized rib pattern can be found based on the environmental conditions and use of the heat exchanger assembly.

FIELD OF THE INVENTION

The present invention relates to automotive heat exchangers, in particular, those with tank and hoses connected to the tank by an inlet or outlet.

BACKGROUND OF THE INVENTION

Automotive heat exchangers typically use hoses, and, particularly, flexible hoses that can be attached to a heat exchanger tank. The flexible hoses are often attached by sliding the end of the hose over the neck of the tank.

A problem with such a hose connection has been the need for a stop or limiter, to limit the distance the hose can slide over the neck. A raised portion of the neck outer surface has been used to act as a “hose-stop” as one solution to this problem. A circumferential raised portion at the open end of the neck has also been used, which acts as a “hose-bead”. The hose-bead acts to seal and retain the hose-neck connection.

A third possible solution to hose placement problems has been the use of a clamping device, and, in particular, a hose-clamping device that is installed on the periphery of the hose where the hose covers or overlaps the neck, most often used at the area of the hose in-between the hose-stop and hose-bead. The hose clamp is tightened circumferentially by a screw arrangement to a diameter slightly less than the hose-bead to retain the hose/clamp assembly against the bead, preventing “hose blow-off” under internal pressure. The clamping pressure also helps to seal the inside of the hose at the bead.

There have been problems associated with these arrangements, however. Permanent deformation of the circular neck cross-section tending it towards a deformed oval shape has been observed in light truck charge-air-coolers. Wherein non-uniformity in the load or the wall strength or stiffness cause the arch effect to be diminished, as the plurality of arches is reduced and/or the circular shape is deformed to a less desirable form. As arch stiffness is diminished, continued deformation, or unstable buckling, can occur, resulting in a permanently deformed/flattened oval shape with a possible loss in sealing.

Current state-of-the-art for high temperature and pressure plastic heat exchanger tanks, as in automotive charge-air-coolers, have reinforced the tank neck by use of a steel sleeve insert. The cylindrical shaped steel sleeve provides added rigidity to the tank neck to help prevent the neck from deforming or buckling under the pressure of the tightened hose-clamp. Though hose clamps are intended to create a uniform radial pressure load on the hose and neck without use of a reinforcing sleeve, in reality there is always some non-uniformity in the load or the wall strength, which can lead to buckling of the cylindrical neck if a steel sleeve is not used. In prior art, circumferential ridges, normally of a small dimension relative to wall thickness, have been provided. Such small circumferential ridges have the advantages as being useful on tank necks to improve hose retention capabilities, but, since they are essentially surface roughness enhancements, and not added piece neck strengtheners, they do not add any significant stiffening to the neck, and, therefore, do not provide the advantages of the present invention.

SUMMARY OF THE INVENTION

The heat exchanger assemblies of the present invention are designed to function under normal heat exchanger environmental conditions, as well as high temperature and/or pressure conditions (severe environmental conditions). Heat exchanger operating pressures and temperatures can be very high, and, due to needs for reduced weight and cost concerns, lighter weight and/or plastic materials, such as plastic CAC tanks, need to be useable under such severe environmental operating conditions, including uses in car as well as light to medium, and possibly, heavy duty truck applications.

Various embodiments of the present invention provide for heat exchanger assemblies, useful under high temperature and/or pressure conditions, without the use of more costly alternatives to maintain hose-neck connections such as enhanced plastic materials, metallic inserts, or improved hose clamps to avoid neck deformation. Other, more elaborate connection schemes that do not rely on clamping pressure, such as quick-connects, will avoid the neck deformation problem, but are significantly more expensive than traditional clamped connections.

The tanks of the heat exchanger, according to an aspect of the present invention, can be made of one or more materials, preferably, the tanks are made of fiber reinforced plastic resin. The neck of the tank is made, preferably, of the same material as the rest of the tank. Tanks with ribbed neck can be made by molding, casting, or machining. Preferably, the tanks made of plastic or plastic like material are made by injection-molding.

Various aspects of the present invention provide for adequate strength at the hose-neck connection, without the need to use higher cost tank material or thicker uniform wall sections to provide for adequate neck rigidity. By providing for a ribbed cross-section, various aspects of the present invention provide a more efficient use of material compared to a uniform thickness wall. Also, in various aspects of the present invention comprising tanks with necks and a rib or ribs, a ribbed cross-section is easier to mold, having less tendency to warp during cooling, compared to a uniform wall with equivalent stiffness. The neck of the tank, in accordance to an aspect of the present invention, can comprise one rib or a plurality (multiple) ribs. An advantage of a plurality of ribs is provision of improved hose sealing and retention capability compared to a smooth wall.

In other aspects of the present invention, the neck comprising exterior or interior rib (groove) can be made of any material that can withstand the severe environmental conditions that the tank and neck are subject to under normal operation. Tanks and necks, for example, in addition to being made of injection molded plastic, can be made of cast metal or formed sheet metal material, such as aluminum, brass, or other copper alloys. A compression hose clamp can be utilized with a flexible hose or duct to form the hose-neck connection.

Various embodiments of the present invention provide for improved neck rigidity in the same overall packaging volume, so that hose dimensions and internal neck flow area are not affected. Neck flow area is generally maintained so that increased pressure loss does not occur due to reduced flow area. By providing ribs or grooves on the external surface of the tank, added stiffening is provided which improves resistance to neck deformation due to elastic or plastic deformation, plastic creep, or buckling, particularly under non-uniform hose clamp loads, and at in severe (high temperature and/or pressure) operating environments.

The present invention, in various embodiments, provides for designs of both necks and hose-neck connections. In various embodiments of the present invention, the neck design is improved so that the neck is provided with increased neck rigidity, without any increase in packaging volume, and without, necessarily, the additional features of steel sleeve or stop and bead, as found in the prior art. When used with hose stops and/or hose beads, even more stable hose-neck connections are provided. Within the same overall packaging volume, the neck and hose-neck connection are of such characteristics that the hose dimensions and internal neck flow areas are not affected by the design.

It has been found that longitudinal structural ribs can be used on tank necks, particularly beyond the end of the hose when the hose is placed in its correct position as part of the hose-neck connection. In an embodiment of the present invention, longitudinal ribs can be used in conjunction with the circumferential ribs in the region where the hose clamp pressure is applied. The circumferential ribs are generally effective at resisting the clamping loads. However, the longitudinal ribs can improve resistance to this load if they are continuous with other stiffening features outside this region, such as an extended rib pattern or the body of the tank, even if they are less effective in retaining the hose. Care is taken so that the longitudinal ribs, if used, do not significantly reduce the retention capabilities of the circumferential ribs.

Structural ribs, as in various aspects of the present invention, have reduced material and tooling cost versus prior art stiffening aids such as steel inserts or the like. In various aspects of the present invention, use of structural ribs means that cost of added material and tooling cost is very small to negligible compared to the total cost of the tank material and molding tool. The added rib material is small compared to the total material in the tank, and the additional one-time tool machining cost for the ribs is small compared to the cost of the tool.

The present invention, in various embodiments, provides for a heat exchanger assembly comprising a heat exchanger with tank having a neck, and, in various embodiments, an assembly further comprising a hose to form a hose-neck connection. In various embodiments, wherein the tank has a neck that is rigid, a hose-neck connection is used that does not require a specific hose design to avoid crushing and does not lead to otherwise inappropriately changing the dimensions of the neck, i.e. internal fluid flow remains unaffected when the hose and neck are assembled. In various embodiments of the present invention, the neck of the tank has basically rounded contours so as to be circular or oval in shape. In particular, the cross sectional area of the neck can be of various forms, but is, preferably, basically circular or oval in shape, which provides for good to excellent sealing with traditional hose clamping arrangements. Oval or elliptical cross-sections, though not optimal for sealing with hose and clamp, are used primarily for packaging or flow contouring. Aspects of the present invention can be well suited for some or all of these shapes as well, since the non-circular shape is also susceptible to deformation when a traditional hose clamp is applied. In non-circular shapes, hose clamps may tend to deform the original shapes toward less desirable configuration, for example, an oval cross section deforming to a more circular cross-section, if the clamping pressure is uniform. In general, the present invention has the advantage that it can improve the ability of the neck to retain its design shape under compressive clamping loads, regardless of the specific shape of the neck.

The various aspects of the present invention allow for a heat exchanger assembly comprising a hose-neck connection, having the advantage of providing for a connection resistant to temperature and pressure conditions of heat exchangers, and, in particular, high temperature and/or pressure heat exchanger assemblies, such as charge air cooler, radiator, or other heat exchanger with flexible hose/duct-to-rigid neck connections. By providing for such a neck on the tank of the heat exchanger, resistance to neck deformation or buckling is increased without the need for, for example, a metallic insert such as a steel sleeve insert.

The present invention, in various aspects, provides for a superior strength-to-cost for given hose inside and outside diameters and neck inside diameter, than available in prior art designs. In addition, by providing for particular rib patterns on the neck, an optimized rib pattern can be found based on the environmental conditions and use of the heat exchanger assembly.

In various aspects of the present invention, a heat exchanger assembly comprising a heat exchanger with a tank having a conduit or ‘neck’ leading from the tank to the exterior environment is provided. By exterior environment it is meant space extending out from the surface of the tank, a neck typically extending out to the exterior environment to a distance required by the design and application of the heat exchanger assembly specification. The minimum distance would be approximately six times the minimal neck wall thicknesses, particularly in aspects as necessary in order to allow space for the hose-bead and at least one circumferential rib.

The tank of a heat exchanger, in accordance with various embodiments of the present invention, is made of plastic resin or metal. The heat exchanger assembly process can include brazing, soldering, welding, adhesive bonding, machining, or mechanical assembly. In brazed heat exchangers, the heat exchanger core, consisting of tubes or fins and tubes, is typically made of aluminum, copper/brass, or stainless steel alloy. Other materials, such as plastics, have been used for cores. The present invention can be applied to any heat exchanger with at least one flexible hose-to-rigid neck connection. By flexible, it is meant that the hose can be deformed to match the rigid surface to a degree sufficient to provide fluid sealing at the interfaces, given the fluids and operating conditions for the application. Rigid implies that the neck deformation is negligible compared to the hose deformation.

In various aspects of the present invention, the heat exchanger core has one or more intakes. In various embodiments, the neck has at least one rib, or, for example, a plurality of ribs. A neck rib, for example, can be a raised or indented portion of a wall relative to the plane of the outside wall of the neck. Ribs can be formed on or added during or after the actual production of the neck. In embodiments with a plurality of ribs, a plurality of structural ribs may be provided. The tank neck has at least one single rib, or more than one rib, or a plurality of ribs running in the same direction, or ribs running in different directions. In various aspects of the present invention, the ribs on the neck of the tank form, alternatively, a rib pattern having exterior ribs (ribs that extend from the general plane of the surface of the tank or are ‘visible’ from the outside of the tank) or interior ribs (grooves, indentations or deformations that extend into the wall of the surface of the neck and are therefore ‘visible’ from the interior of the tank) that form, thereby, heightened or depressed areas relative to the plane of the surface of the neck. In various aspects of the present invention, the rib pattern provides for a heat exchanger tank neck that withstands various environmental conditions. For example, when internal pressure within the at least one tank of the heat exchanger increases, a gripping effect is provided by the rib pattern on the neck of the tank that causes the hose, when assembled to the neck of the tank at the hose-neck connection, to be retained, in spite of the severe conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates three views of a prior art heat exchanger tank neck design, including cross section of tank heading having metallic sleeve.

FIG. 2 illustrates a heat exchanger failure modes in prior art designs, having deformation of circular tank necks.

FIG. 3 is a schematic view of a heat exchanger neck with longitudinal cross section and exploded views with circumferential ribs, in accordance with an aspect of the present invention

FIG. 4 is a schematic view of examples of rib designs in cross section, applicable in various aspects of the present invention.

FIG. 5 is an overhead cross sectional schematic view of a non-circular neck with tapering or varying height of circumferential rib, in accordance with an aspect of the present invention.

FIG. 6 is a schematic, longitudinal view of the neck of a tank having no hose bead, in accordance with an aspect of the present invention.

FIG. 7 is a schematic view of interrupted, staggered or longitudinal assisted circumferential ribs, in accordance with an aspect of the present invention.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE PRESENT INVENTION

In various aspects of the present invention, a heat exchanger assembly comprising: a core comprising a tube or tubes; a manifold, a hose having flexible attachment area for attachment to a manifold neck; a manifold neck of greater relative stiffness when compared to the hose, which serves as a fluid inlet or outlet on the manifold; and at least two ribs on the part of the manifold neck that extends into the environment exterior to the manifold is disclosed. In various aspects, at least one of the at least two ribs on the manifold neck is a circumferential or essentially circumferential rib; and wherein the hose, neck and ribs form a hose-neck connection comprising sealing surfaces which form a hose to neck seal that is essentially leak tight to the exterior of the heat exchanger.

Aspects of the present invention include heat exchangers assembly comprising a hose bead on the manifold neck, such that the sealing surfaces maintain an essentially leak tight seal while helping to provide integrity to the hose-neck connection. In addition, various aspects comprise a clamp at the hose-neck connection. Where a hose bead is present, in various aspects the hose bead is tapered so as to allow for variable pressure on the bead to the hose at different areas of the hose-neck connection.

Heat exchanger tubes, in various aspects of the present invention have cross sectional areas of the tube at the area of the hose-neck connection that can be basically circular or non-circular. In many embodiments, the cross sectional area of the tube at the area of the hose-neck connection is basically circular. Also, the neck of the heat exchanger assembly, in various aspects, has a plurality of ribs at the neck in the area of the hose-neck connection, and wherein the plurality of ribs is essentially circumferential and of approximately the same height when measured from the outer surface of the neck. The plurality of ribs, in any case, can be essentially circumferential and of approximately the same height when measured from the outer surface of the neck.

As describes herein, ribs can be of various shapes and sizes. For example, in various aspects, at least one of the plurality of ribs is a squared rib. Also, in various aspects, at least one of the plurality of ribs is a tapered or radiused rib. In various aspects of the present invention, essentially circumferential ribs are selected from the group consisting of rectangular, tapered, radiused or corrugated ribs. Also, ribs can be symmetric or non-symmetric. In various aspects of the present invention, at least one of the ribs is a non-symmetric rib. Also, ribs can vary in height along the circumference of the neck. For example, in various aspects of the present invention, a heat exchanger assembly is present, wherein the cross sectional area of the tube at the hose-neck connection is basically non-circular, and wherein the at least one circumferential or essentially circumferential rib varies in height along the circumference.

Under stress, such as that caused by high pressure or the like, the hose-neck connection can be disrupted due to deformation of the neck at the area of the connection. For example, a deformation or a change of shape of the neck, if significant enough, can cause a weakening of the seal strength between the neck and the hose, leading for example, to reduced integrity of the seal between the hose and neck at the heat exchanger inlet or outlet.

Prior art FIGS. 1 and 2 are provided.

FIG. 1 a shows a plastic tank (1) having neck (3) extending to exterior of the tank (2) and external vertical structural rib (2 a, 2 b) with part extending from tank body (2 b). Steel sleeve (4) is placed inside neck (3) after molding.

FIG. 1 b is a face on view of neck (3) from exterior to interior of the tank, and cross sectional axis A-A is illustrated.

FIG. 1 c illustrates cross sectional view from 1 b including hose (5) and have clamp (7), which applies pressure F to compress hose against neck (3). Metallic sleeve (4) inserted at neck (3) provides additional stiffness. Internal pressure along line P tends to pull hose (5) off neck (3).

As seen in FIGS. 2 a-c, necks (23 a, 23 b, 23 c) are shown. In necks (23 a, 23 b, 23 c) without metallic neck inserts, pressure loads, as indicated by arrows 26, and 25, show uniform pressures, such as hose clamp pressures (26) as well as non-uniform hose-clamp load or wall strength (27) that can cause indeed bending movements (A, B, C, D) leading to loss of arch strength and onset of unstable buckling.

FIG. 2 c specifically shows a permanent deformation to oval shape that result in seal leakage/reduction in seal integrity versus the drawing requirements. In various aspects of the present invention, use of essentially circumferential ribs on the neck at the area of the hose-neck connection leads to resistance to wall bending movements induced by non-uniform loads and deformation and increased integrity of the seals at the hose-neck connection or junction. As load is applied, deformation of original shape leading to reduced seal integrity occurs.

FIG. 3 illustrates one aspect of the present invention. Circumferential stiffening ribs (30) are placed or molded or otherwise formed on the outside of the tank neck (32) in the region (R) where the hose (34) overlaps the neck (32), between the hose-bead (35) and hose-stop (37). The height of the ribs is less than the height of the hose-bead, and, can, in certain variations, be just slightly less than the hose-bead, so that the hose (34) can slide over the ribs (30), and a hose clamp (not shown), which would typically be used, can be tightened to compress the hose inside diameter to slightly less then the hose-bead outer diameter. The hose (34) is compressed into the spaces (38) between the ribs (30), to provide additional grip to prevent hose blow-off. Such rib patterns increase resistance to neck deformation while maintaining hose retention characteristics. The ribs could also be essentially circumferential in nature, for example, tapered (i.e. varying height) as they go around the circumference. Internal pressure along line P tends to pull hose (34) off neck (32).

In another embodiment of the present invention, ribs are essentially circumferential in nature, i.e. they can be continuous or partially discontinuous, or discontinuous, have equal height or be tapered around the circumference, etc., as long as they function in a way that they provide a surface effect around the circumference of the neck in such a way that a ‘grip’ or ‘hold’ is maintainable at the hose-neck connection.

Ribs, therefore can provide stiffness, as well as grip and retain a hose. The hose can deform into the grooves or spaces between ribs to further help grip and retain the hose. Taller, essentially circumferential ribs, particularly if used after the hose grip area, can add to stiffness of the neck, as well as act as a hose-stop.

In various aspects of the present invention, the neck of the tank is basically, essentially circularly cross-sectional in nature. The neck of the tank, in various aspects, has an arch shape or shape composed of a plurality of arches. Such an arch shape is basically circular for optimum rigidity and sealing characteristics with a traditional hose clamp, allowing for effective fluid transfer under compressive radial hose clamp loads. By retaining its basically circular shape, the arch effect allows for the neck to retain its basic strength and allow flow to run basically unobstructed throughout its length (“arch” effect). As described herein, the direction of force due to internal pressure (see FIG. 1 c), for example, could tend to displace a hose-neck connection of prior art configuration. Essentially circumferential ribs allow maintenance of a standard hose dimension and tank neck inside diameter with greater grip to have a better seal.

In various embodiments comprising exterior, rather than interior ribs, the outside location of the ribs allows operation at cooler temperatures to reduce material strength degradation due to high temperature, avoid the interior rib potential problems of internal flow blockage and pressure loss, and allowing operation at higher temperature due to exposure to the hot internal flow.

In various aspects of the present invention, ribs are provided so that they are in an essentially circumferential pattern in the locations where the hose clamp, hose, and tank neck overlap. In embodiments of the present invention having necks with beads, the ribs are slightly lower than the hose bead to allow the hose to slide over them, and to allow the hose to be compressed by the hose clamp to a slightly smaller diameter than the bead for improved hose retention. The dimensions of the ribs can vary to provide more rigidity and/or more hose-retention capability at the hose-neck connection. Dimensions of these ribs are optimized to provide the best combination of rigidity and hose-retention features for a given application. The height of ribs outside of the hose-overlap region can be greater than the hose inside diameter, providing increased stiffening compared to the ribs overlapped by the hose, as well as acting to limit the overlap of the hose on the neck, thereby locating the hose. Ribs are added at the end of the hose in various aspects of the present invention, are used, for example, for increased stiffening and to act as a hose-stop. For example, in various aspects of the present invention, circumferential ribs at the end of the hose can act as a hose-stop, as well as a stiffening device.

In FIG. 4 is illustrated various examples of shapes of essentially circumferential ribs useful in various aspects of the present invention. So called rectangular rib (42), has sharp edges (41 a, 41 b) of essentially 90° in various locations. ‘Tapered’ ribs (44) have one or more edges (43 a, 43 b) of greater than 90° in various locations. Non-symmetric ribs (45) have edges of different value, for example 90° (45 b) and greater than 90° (45 a) in some ribs. Tapered/radiused ribs (46) have at least one rounded edge (47, 48) or radius, and, preferably, more than one rounded edge. Corrugated ribs can have shapes that include the above features, but are generally formed from a sheet of uniform wall thickness, such that the ribs/features will be internal (visible from inside), as well as external (visible from the outside).

In FIG. 5 is illustrated a noncircular neck (52) in cross section with rib (50) heights (H1, H2) varying to optimize sealing and/or stiffness requirements.

In FIG. 6 is illustrated a tank neck (62) at area of future hose-neck connection J, where the first rib (60) with tapered lead (61), serves a function similar to that normally served by a hose bead (no hose bead present).

In FIG. 7 is illustrated examples of basically circumferential ribs (70) with longitudinal ribs (74) or rib interruptions (76) or staggering (75) of rib portions.

Interrupted or staggered ribs are located in an essentially circumferential pattern around the heat exchanger assembly neck. The neck-hose connection is thereby maintained in good integrity.

Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. Plural structural components can be provided by a single integrated structure. Alternatively, a single integrated structure might be divided into separate plural components. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention.

The preferred embodiment of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention. 

1. A heat exchanger assembly comprising: a core comprising a tube or tubes; a manifold; a hose having flexible attachment area for attachment to a manifold neck; a manifold neck of greater relative stiffness when compared to the hose, which serves as a fluid inlet or outlet on the manifold; and at least two ribs on the part of the manifold neck that extends into the environment exterior to the manifold; at least one of the at least two ribs on the manifold neck is a circumferential or essentially circumferential rib; and wherein the hose, neck and ribs form a hose-neck connection comprising sealing surfaces which form a hose to neck seal that is essentially leak tight to the exterior of the heat exchanger.
 2. A heat exchanger assembly as in claim 1, comprising a hose bead on the manifold neck, such that the sealing surfaces maintain an essentially leak tight seal while helping to provide integrity to the hose-neck connection.
 3. A heat exchanger assembly as in claim 1, further comprising a clamp at the hose-neck connection.
 4. A heat exchanger assembly as in claim 2, further comprising a clamp at the hose-neck connection.
 5. A heat exchanger assembly as in claim 4, further comprising a hose bead, wherein the hose bead is tapered so as to allow for variable pressure on the bead to the hose at different areas of the hose-neck connection.
 6. A heat exchanger assembly as in claim 3, wherein the cross sectional area of the tube at the area of the hose-neck connection is basically circular or non-circular.
 7. A heat exchanger assembly as in claim 6, wherein the cross sectional area of the tube at the area of the hose-neck connection is basically circular.
 8. A heat exchanger assembly as in claim 6, having a plurality of ribs at the neck in the area of the hose-neck connection, and wherein the plurality of ribs is essentially circumferential and of approximately the same height when measured from the outer surface of the neck.
 9. A heat exchanger assembly as in claim 7, having a plurality of ribs at the neck in the area of the hose-neck connection, and wherein the plurality of ribs are essentially circumferential and of approximately the same height when measured from the outer surface of the neck.
 10. A heat exchanger assembly as in claim 6, wherein at least one of the plurality of ribs is a squared rib.
 11. A heat exchanger assembly as in claim 6, wherein at least one of the plurality of ribs is a tapered or radiused rib.
 12. A heat exchanger assembly as in claim 6, wherein the essentially circumferential ribs are selected from the group consisting of rectangular, tapered, radiused or corrugated ribs.
 13. A heat exchanger assembly as in claim 12, wherein at least one of the ribs is a non-symmetric rib.
 14. A heat exchanger assembly as in claim 7, wherein the diameter of the flexible tube is slightly less than the diameter of the neck, such that the tube provides pressure on the ribs when part of the hose-neck connection.
 15. A heat exchanger assembly as in claim 3, wherein the cross sectional area of the tube at the hose-neck connection is basically non-circular, and wherein the at least one circumferential or essentially circumferential rib varies in height along the circumference.
 16. A heat exchanger assembly as in claim 2, wherein the essentially circumferential ribs are selected from the group consisting of rectangular, tapered, radiused or corrugated ribs.
 17. A heat exchanger as in claim 16, wherein the diameter of the flexible tube is slightly less than the diameter of the neck, such that the tube provides pressure on the ribs when part of the hose-neck connection. 